\item \lect Look at the following statements and tick them if they are true.

\begin{itemize}
\item[$\square$] In a sequent, premises entail a conclusion.
\item[$\square$] In a sequent, conclusions entail a premise.
\item[$\square$] A sequent is valid, independent on whether a proof can be found.
\item[$\square$] A sequent is valid, if a proof for it can be found.

\end{itemize}